The Maoist insurgency gripping India's heartland has been blamed for more than 800 violent deaths this year, and will soon be a target of a major counter-offensive by Indian security forces. But the so-called Naxalite movement  as well as the fight against it  has a hidden cost: the education of thousands of India's most vulnerable children, whose schools have been blasted by rebels, occupied by security forces, or both.

A report released Dec. 9 by Human Rights Watch found that at least 39 schools in the Eastern states of Jharkhand and Bihar have been attacked by Naxals in the last year. That doesn't include schools that are occupied by state security forces, of which the total number is still unknown. "When we wanted to know of the exact number of schools that were being occupied by the security forces, the government refused to provide us the details," says Subrata Bhattacharjee, president of the Jharkhand chapter of the People's Union For Civil Liberties (PUCL), an advocacy group based in that state. The PUCL filed a public-interest lawsuit in Jharkhand and found that 52 schools in that state were occupied. Despite an order issued by the state supreme court to vacate the schools by January 2009, all but 13 remain occupied. (See pictures of a Jihadist's journey.)

The insurgency's effect on education has been devastating. The Naxalite movement has been agitating for revolution in India's long-neglected rural interior since 1967, and sees any government building as an emblem of the state it seeks to overthrow. Naxal attacks usually occur at night, when improvised explosive devices, known as "can bombs," are set off inside the schools. Human Rights Watch researchers visited a school in Dwarika, a village in Jharkhand where no classes have been taught since a can bomb explosion severely damaged the building in November 2008. The wooden doors were shattered, and the walls cracked, making the brick building unsafe for students. Of the 250 students, only 50 had families with enough money to send them to the next village. "We are poor people," said one father in Dwarika, whose children stay home, grazing cattle. "Those who are not able, how can they send?"

Just as damaging is the occupation of all or part of a school building by security forces, who use them as camps or barracks. Students are squeezed into the remaining parts of the school, which in many cases stops functioning altogether. Megha, a high school student in the Mohulia district of Jharkhand, says two-thirds of her school is occupied by troops. "We cannot go to the toilets, as they are used by camp people," she said in an interview with TIME. Other students complain of harassment  the girls feeling leered at, and the boys grilled for information about suspected insurgents in the village. At the Tankuppa High School in Bihar's Gaya district, a 16-year-old student told HRW that the police "bring culprits back to the school and beat them." (See the top 10 underreported stories of 2009.)

As the Indian police and paramilitary forces gear up for a big push against the Naxals planned for early next year, the impact on schools is likely to get worse. In remote areas, schools may be the only solid construction available to use as a base of operation. State education officials say the schools are occupied only temporarily, and that alternative sites are arranged, but residents of Naxal-affected areas say that many schools have been closed for months or years, permanently disrupting education. Burhan Soren, a farmer in Gurha, says one school in his village has been occupied since 2003. "As the father of two small children, I feel very strongly about this," Soren tells TIME. "But if we protest too much, then the government says we are aligning with the Naxals."

The insurgents, too, insist that they only attack schools that are being used as "police camps." In the November 2008 bulletin of a banned Maoist political party, an unsigned editorial states, "You cannot show a single instance where we had destroyed a school that was really meant for education purposes." HRW researchers contradict that claim, and say the Naxals attack schools as a way of intimidating the local population to keep them from cooperating with the military, who badly need better local intelligence.

The government school systems in Bihar and Jharkhand were already abysmal well before Naxal activity picked up this year. Average class sizes in the two states are 75 and 65, respectively, for a single teacher, compared to the national average of 40. Literacy rates, too, are well below the national average of 65%. Indian Prime Minister Manmohan Singh has made development in Naxal-affected areas  including education  a priority, but the attacks and occupation threaten to undo what limited progress his government had made. In the Aurangabad district of Bihar, for example, the government approved about $28,600 to build a residential school for poor girls in late 2008. Once 10 police officers occupied part of the school this year, no family would enroll their daughters, and the school has yet to open. (See pictures of Singh at President Obama's state dinner.)

Human Rights Watch is calling on the Naxal groups to stop targeting school buildings, and for state authorities to repair damaged buildings and provide viable alternatives for occupied schools more quickly. Its representatives will be meeting with Indian central government officials about the issue this week. In the meantime, thousands of students in the affected areas are missing yet another year's exams. "The government says it is in the interest of the children that the security forces stay in the schools to guard against Maoist activities," Bhattacharjee says. "The Maoists say they blow up schools because they are less educational institutions and more security camps. So, ultimately the villagers get caught in the crossfire."